Preheat your oven to 400°F (200°C). Wash and prick the sweet potatoes with a fork, then bake on a baking sheet for 40-45 minutes until tender. Allow to cool slightly before peeling.

Lower oven temperature to 350°F (175°C) and grease a 2-quart baking dish with unsalted butter. Set aside.

In a food processor, blend 2.5 peeled sweet potatoes with unsalted butter, milk, brown sugar, vanilla extract, cinnamon, salt, and eggs until smooth and creamy.

Mash the remaining half sweet potato by hand with a fork and fold it into the blended mixture along with the orange zest.

Pour the sweet potato mixture into the greased baking dish and spread evenly.

In a mixing bowl, combine chopped pecans, flour, brown sugar, and salt. Drizzle melted butter over the top and stir until clumpy.

Sprinkle the pecan crumble topping over the sweet potato mixture and bake for 25-30 minutes, until the center is set and topping is golden brown.